Add web assembly using rustler + wasmtime

Author: RoyalIcing

lib/components_guide/rustler/math.ex

@@ -19,6 +19,7 @@ defmodule ComponentsGuide.Rustler.Math do
 
   def add(_, _), do: error()
   def reverse_string(_), do: error()
+  def wasm_example(_, _), do: error()
 
   defp error, do: :erlang.nif_error(:nif_not_loaded)
 end

lib/components_guide_web/controllers/cheatsheets_controller.ex

@@ -2,8 +2,16 @@ defmodule ComponentsGuideWeb.CheatsheetsController do
   use ComponentsGuideWeb, :controller
   require Logger
 
+  @wasm_constant """
+  (module
+    (func (export "answer") (result i32)
+     i32.const 42
+    )
+  )
+  """
+
   def index(conn, _params) do
-    render(conn, "index.html", article: "intro")
+    render(conn, "index.html", article: "intro", wasm_constant: @wasm_constant)
   end
 
   @articles ["rxjs"]

lib/components_guide_web/templates/cheatsheets/index.html.eex

@@ -2,8 +2,8 @@
 
 <article>
   <div class="text-white bg-gray-900">
-    <div class="content max-w-4xl mx-auto py-8 text-xl" style="--link-decoration: underline;">
-      <%= render(view_module(@conn), @article <> ".html", conn: @conn) %>
+    <div class="prose md:prose-xl prose-invert max-w-4xl mx-auto py-16">
+      <%= render(view_module(@conn), @article <> ".html", assigns) %>
     </div>
   </div>
 </article>

lib/components_guide_web/templates/cheatsheets/intro.html.md

@@ -1,5 +1,6 @@
 Various cheatsheets will be added over time. If you have ideas for cheatsheets, please submit them.
 
-<p><%= 6 + 1 %></p>
-<p><%= ComponentsGuide.Rustler.Math.add(5, 9) %></p>
-<p><%= ComponentsGuide.Rustler.Math.reverse_string("hello") %></p>
+<p>From Elixir: <%= 6 + 1 %></p>
+<p>From Rust: <%= ComponentsGuide.Rustler.Math.add(5, 9) %></p>
+<p>From Rust: <%= ComponentsGuide.Rustler.Math.reverse_string("hello") %></p>
+<p>Fromst WebAssembly + Rust: <%= inspect(ComponentsGuide.Rustler.Math.wasm_example(@wasm_constant, "answer")) %></p>